Multiplexed collision induced dissociation (CID) experiments, traditionally performed by axially exciting an ion population, suffer from under or over-fragmentation. The entire range of analyte ions is typically not dissociated by one selected collision energy. Though collision energies may be scanned to induce fragmentation over a wider range of precursor ions, this typically results in fragmentation of the fragment ions, yielding spectra that contain mostly secondary fragments that are not useful for structural characterization.
A method that dissociates a wide range of precursor ions while leaving the fragment ions intact is desired.